


Gaster Blaster Mom

by AnimefangirlPeggy65



Category: Undertale
Genre: Alternate Universe, Baby bones Sans and Paps, But they won't be as important I don't think, Crack, F/M, Fluff, Gaster doesn't approve of reader taking in Sans and Paps, Gen, Hijinks, Humor, I don't know, Motherly Reader, Overprotective older brother Sans, Possible Dadster Gaster, Possible Gaster/Reader - Freeform, Random Stuff!, Reader can shape shift, Reader is Gaster's test subject, Reader is somewhat of a big influence on Sans and Papyrus, Reader knows and lives with Gaster, Reader likes puns, Reader's soul is fused with a Gaster Blaster, So is Gaster, hybrid reader, other characters may appear - Freeform, puns
Language: English
Status: In-Progress
Published: 2016-07-01
Updated: 2017-05-22
Packaged: 2018-07-19 08:28:59
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 5
Words: 7,514
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7353484
Author URL: https://archiveofourown.org/users/AnimefangirlPeggy65/pseuds/AnimefangirlPeggy65
Summary: <blockquote class="userstuff">
              <p>"Gaster, I'm keeping them, and there's nothing you can say to make me think otherwise." </p><p>-------------------------------</p><p>In a world where a human fell into the Undergroud shortly after Chara, they found themselves discovered by someone other than the Dreemur family. They were found by the brilliant scientist, W.D. Gaster. The human became a willing test subject as they'd already given up on life, but found a new purpose when bonded with one of W.D. Gaster's creations, the Gaster Blaster. With her newfound abilities, she now can wield magic and shape shift between her human form and a full bodied Gaster Blaster that is a lot bigger than her human form and helps her blend in a little. But not just her new powers gave her the push to keep on wanting to live. There was a new added factor that gave her the spark to keep living. Two little beacons of light had wondered into her life and she would not be willing to let them go after taking them in. No, mama was gonna protect and care for her babies until the very end, no matter what Gaster said or thought.</p>
            </blockquote>





	1. Bringing home strays

**Author's Note:**

> Just a random idea. I still plan to continue on my Mettaton one, but I couldn't help typing down this idea when it came to me.

To ______, the day started out as what she considered 'normal.' Life in the Underground was a lot different than on the Surface. Very different, but not in a completely bad way. Everyone was nice to her unlike in the world above where most are mean and out to hurt you in some way, whether it be physical or mental.

 

-P.O.V. swap-

 

It was a quiet, normal day for you. As you wondered the Hotlands outside the lab, waded the waters of the Waterfall, and walked in the snow of Snowdin, you soon came to a stop near the entrance to the Ruins. There was some nagging instinct inside your soul that pulled and tugged on you to wander the forest near the Ruins.

 

You felt like some overly large dog with the looks of a dragon scarce of wings in your Gaster Blaster form, your large feet trampling in the snow, your boney body vainly trying to avoid tree branches that snapped upon impact with your strong bones as you treaded through the forest as lightly as you could.

 

Your human body did feel this urging in your soul, but you feared it may be someone wanting to hurt you, so you stayed in your stronger form. Despite most of the monsters being nice, some were not and attacked you. You didn't want to get hurt in your weak fleshy form, so you stayed like this. The feeling was strong this way and your bones wracked with something akin to silent joy. To what, you didn't know yet.

 

Not until you heard it. It was a small whimper like noise and a low 'Shh!' of sorts. Your head whipped to the left, finding a space between two large rock structures. It was thin, too thin for this form, but your human form may be able to squeeze in. As you lowered your head, you lit up your eye to peer inside. What you found had given you quite the shock.

 

-Time skip and P.O.V. swap-

 

Gaster was her creator, her roommate, her friend, and her landlord in a way.

 

She did not have to pay him for her stay, only continue to be examined as she was now bonded with one of his creations, the Gaster Blaster. As a willing test subject, she told him all that he needed to know of human bodies and let him poke and prod at her. He'd done nothing too bad aside from the process of bonding her with a Gaster Blaster.

 

He didn't exactly cut her open and sew her back together during his examinations, but he did like to feel of the bone under her flesh, saying she was 'remarkable' and 'not like monsters.' He never got too handsy with her, but did ask questions and examined her on a daily basis. As for bonding her with a Gaster Blaster, he did do some surgery on her.

 

By giving her the eye of a Gaster Blaster, the two had somehow bonded souls, becoming one being. However, where Gaster Blasters had very little mind of their own and had to be ordered to do things, ______ had full rein of their combined bodies.

 

Now, as for ______ being able to turn into a full bodied Gaster Blaster, Gaster had only recently began to make only the heads as they were easier to summon and control than the larger beasts which required more magic to do so. What agitated Gaster a bit at times was that ______ did have a mind of her own and could not be controlled even if she was part Gaster Blaster which were created to serve.

 

Which is why he was in this predicament. Apparently, _______ had brought in strays and she was set on keeping them. From one look at the strays, he knew they were going to be trouble, which is why he told her no. However, she did not like that answer. She first held a look of shock, but that was quickly replaced by a sharp glare.

 

"Gaster, I'm keeping them, and there's nothing you can say to make me think otherwise."

 

Oh no. She was even giving him the _look_. That look meant nothing but trouble. It meant she was mad and would use force if she felt it necessary. She was anything but weak, and that glowing eye of blue meant trouble. It meant her magic was activated and ready to be used. So, with no other choice, Gaster sighed and gave in. It was by far, one of the worst mistakes and blessings he'd ever made.

 

-Earlier, your P.O.V.-

 

You'd found two tiny skeletons inside that small crevice between the rocks. There was a taller, bigger boned one and a smaller, thin boned one. If you didn't know any better you'd say they were brothers. Your Gaster Blaster form's eye sockets rose a bit in shock before your gaze softened and you switched forms since they seemed rather scared of your other one.

 

However, despite their fear, you could see the taller push the smaller behind him in a protective manner. You approached the small opening and crouched down near the entrance.

 

"Hey, there. Come on out, I won't hurt you. What are you two doing out here all alone, huh?" You asked in a calm, soothing voice.

 

It was then you knew that you were definitely keeping these two. Especially when they informed you that they had no caretaker. You were taking care of them whether Gaster liked it or not.


	2. Sandwiches

**Summary for the Chapter:**

> Lesson: Do NOT let Pap bite you. Just- don't...Unless you have healing powers of some sort.

_"How long have you guys been there?"_

 

_"I dunno. Two, three days."_

 

_"With no food?" He shook his head in response. "Three days without food?! You must be starving! Come, you can stay with me. I live with the royal scientist. Food is no problem. We're practically loaded."_

 

_You began to carry the two back to Hotlands, all the while asking questions and telling about yourself._

 

_"How old are you two?"_

 

_"I'm eight and Paps here is three."_

 

_"And your name is Sans, right?"_

 

_"Yup. And this here is Pap. Well, that's what I call him. His full name is Papyrus."_

 

_Well, I'm _______, but you can call me mom since you don't have any."_

 

_"Yeah...They-...They've been gone for some time"_

 

_"Well, worry not. I shall take care of you now."_

 

\-----------------------------------------

 

Gaster had gone back to work not long after you'd claimed the two skeleton brothers as your own. You had them sit in the kitchen with the intentions of making them something to eat. It was a surprise they hadn't starved yet.

 

Despite being skeletons, all monsters needed food. Gaster had explained that to you the first time you asked him about it since he's also a skeleton himself. You tried not to pry too much into his personal life.

 

He didn't like socializing unless he was educating you on something or you were telling him about the human body. He practically lived on fast foods and told you to simply 'find yourself something to eat.'

 

He was rather lazy about doing things or putting things away if they weren't clotting up his work space and back when you were careless and just wanted to die, you didn't care either.

 

You'd just lie on the floor with his dirty lab coats and clothes and sigh, wishing you could just die already. Now, however, you had this urge to make things clean and safe. Perhaps it was the presence of your adopted sons?

 

Something had sparked back to life inside you upon meeting them. You wanted to make them safe, happy, and healthy and in doing so you needed to be safe, happy, and healthy. And the first step would be to make something to eat.

 

You thought, 'Why the hell not?' and went to ask Gaster if he wanted anything to eat after telling Sans and Papyrus to take a seat in the kitchen.

 

"Stay here. I'll be right back. I'm going ask Gaster if he wants anything to eat."

 

"Ok." Sans said, holding his younger brother since he wasn't exactly able to sit in a seat by himself and be safe.

 

Papyrus was only three, after all. You headed towards Gaster's lab, knowing full well he'd very likely be in there. It wasn't very often that he wasn't. You peeked in, knocking lightly on the wall since the door was open, but you didn't want to intrude.

 

"Gaster, want anything to eat?"

 

"How many times have I told you not to-" He cut himself short, angry tone fading. "Wait. Why?" He drawled out, turning to you with a stack of papers in hand.

 

"I figured I'd cook something for the boys and figured I'd ask if you wanted anything, why?" Gaster dropped his papers, jaw falling open as though you'd just traveled through time and space or something.

 

"Wh-" You started, but were cut off.

 

"You're actually _cooking_?" It was your turn to drawl out your words.

 

"Yeah. I don't see what the big deal is. I've cooked before."

 

"Yes, but- I've never seen you do anything before aside from lie on the floor and wish your life would disappear from existence! This is- Amazing! You're actually _doing_ something! And look! Your eyes aren't a dull grey anymore! They're actually (e/c)!"

 

As Gaster rambled on, you started to feel mighty uncomfortable. Okay, so what if you were actually doing something aside from lying on the floor wishing you'd just die already? It was strange that he was more excited about it than you.

 

"Just think of the results and new powers you could unlock if you actually put forth effort during the tests and training! This could be a break through!"

 

Oh. Well, that explains it. You felt a bit dejected at Gaster's words. It was asinine of you to feel that Gaster would actually care about you getting out of your deep depression. How could you be such a fool?

 

He only cared about his research and scientific findings. Your life was nothing, but a front row seat to him for examining humans.

 

Kinda angry and saddened at his implying that this was new openings for his research, you tried to mask your face of slight disappointment and anger.

 

"I'll be in the kitchen. Don't bother with me unless you need anything." 'I don't want to feel even worse with your talk of test and research right now.' You thought.

 

He continued with his rambling as though he hadn't heard you, so angry and hurt, you headed to the kitchen to whip something up.

 

\-------------

 

"So, Sans, what is it you'd like to eat?" You asked, looking in the fridge.

 

Just seeing the two made your spirits rise. That Gaster... Honestly, how had you thought he'd care? Why did you want him to care? Hmph. You shook the thought away when Sans spoke up.

 

"Oh, uh...Anything's fine, I guess."

 

'Something quick'd be nice.' You thought.

 

The two were probably famished. No cooking. It'd take too long.

 

"Are sandwiches alright?"

 

"Sure. Anything sounds good about now."

 

Uh oh. Momma Blaster mode was activated. You were going to make these kids the biggest sandwich you could offer. They needed food and they needed it now. You were quick, but careful in assembling the sandwiches.

 

It wasn't until you had them made that a thought hit you.

 

"Hey, uh, Sans?"

 

"Yeah?"

 

"Papyrus can eat a sandwich, right?"

 

"Heh. Sure can. He's got quite a bite." Sans said, almost sounding boastful. "My bro's nothing but cool. You shoulda seen how hard he bit me once. Man, that was painful." You smiled lightly, happy that Sans sounded happy talking about his little bro.

 

You could feel your heart radiate with affection towards the two.

 

"Here." You said, placing the plates with the sandwiches down in front of Sans and Papyrus. "Why don't I hold Papyrus while you eat?" You saw Sans visibly stiffen at your words and you couldn't help but notice Papyrus trying his best to reach the sandwich on the table.

 

His eyes were squinted in concentration as he tried his best to reach the sandwich from his spot with his tiny arms, fighting against Sans' hold on him in doing so.

 

"I guess, but... **If you hurt my bro, you're going to have a bad time**." Sans' eye sockets went dark, white pinpricks disappearing.

 

His tone had even changed. It went from the sweet innocent voice, to a deeper, darker tone. You were a bit shocked at first, but recovered quickly, placing your hands on your hips and replying in a more playful tone.

 

"I have no intentions of hurting you or your brother, but..." You trailed off, eye going light blue. "I don't think you know who you're dealing with here, mister. **I'm the master of bad times**."

 

Sans seemed a bit shocked like you were earlier, but in his slight daze handed you Papyrus. You took him from his older brother's arms and placed Papyrus at your hip, reaching down to grab the sandwich from Papyrus' plate and handed it to him.

 

Papyrus' expression lit up with glee as he let out what sounded like a 'Nyeh!' in the form or a squeal and took the sandwich from your hands gratefully, taking a big chomp out of it. Sans still sat in a daze, staring at you with empty eye sockets.

 

"Woah...So cool..." He muttered before he regained his composure and began scarfing his sandwich down too.

 

You chuckled lightly when Papyrus let out a 'bleh' at the taste of something in the sandwich . You looked down at him to see he did not like the mayonnaise at all.

 

He removed the top bread which had mayonnaise on it and the lettuce which had mayonnaise spread on it from the bread and tossed them in the floor.

 

"Hey, you." You scolded in a light hearted voice that was more playful than anything. "You shouldn't be throwing stuff in the floor. If you didn't want it, you could have told me so or handed it to me." You poked him on his cheekbone lightly for emphasis.

 

"Hey, uhm...Mom?" Sans said nervously, as though he was slightly afraid or felt awkward calling you 'mom.'

 

"Yes?"

 

"What's this red stuff? It tastes pretty good."

 

"The tomatoes or- Oh! Ketchup?"

 

"Yeah! Do you think...I could have some more?"

 

"Why sure!" You said, walking over to the fridge and getting the ketchup out, closing the door with a foot as you still had Papyrus in your arms. "Here you go!"

 

"Thanks." What neither of you expected, though, was for the lid to fall off and for ketchup to completely cover Sans' sandwich .

 

"Oh my gosh! I am so sorry! I didn't know the lid would fall off! Here, I'll make you another-"

 

"No, no. It's okay."

 

"You sure? You sure you don't want me to make you an other sandwich ?"

 

"I'm sure." He lifted the sandwich, covering his boney hands in ketchup in the process, and proceeded to eat the sandwich anyway. "Hmm...This is pretty good." He said.

 

Though you were internally cringing at how all that ketchup may taste, you were just happy that he was enjoying the sandwich .

 

"Augh!" You cried out as a sharp pain ran through your finger.

 

You looked down to see Papyrus had latched his teeth onto your finger. He'd brought the blood out of you and you could feel your bones about to split under the strength of his jaws. He let go of your finger when he caught a taste of your blood.

 

You inspected your finger, watching as your broken skin patched itself together with your regeneration powers.

 

"I tried to tell ya." Sans said from his spot, having fully finished his sandwich and was now licking the ketchup from his hands and the plate.

 

'Note to self: Don't let Papyrus bite you. Ever.'

**Notes for the Chapter:**

> Because lets be honest, the mental image of a three-year-old Papyrus taking a big bite out of something then going 'Bleh!' because he doesn't like how it tastes is adorable.


	3. Testing the waters

**Summary for the Chapter:**

> Gaster manages to piss Momma Blaster off.

After your finger healed up completely, you gave Papyrus some monster candy to snack on since he still seemed a bit hungry. To make things even, you also gave some to Sans, as well. 

"You guys can sleep in my room until I fix a better place for you two. Most rooms are filled with junk or with Gaster's stuff for research and he doesn't like me touching his stuff. So, if you need me, I'll be on the couch and you two can have my bed. Sound good?" 

"Sure." 

"Great. Then we can head up to the capital tomorrow and get you guys some things. It's already late evening and I don't want to travel until I know we have plenty of time. Surely you guys will tire once dark hits and be yearning for a warm, comfortable place to sleep." 

"Yeah...That cave floor wasn't very comfortable." 

"I'd assume not. Though you don't have to worry much more. I intend to take good care of you two. No children ever should be treated poorly and neither should anyone else. You two are my sons now and I refuse to let anything happen to you or to let anyone treat you unjustly. I expect you to come to me if you need anything, have any problems, concerns, or questions."

"Got it." 

You went to open your mouth and speak, but Gaster cut you off. 

"_______! Come here! It's time we test your powers again!" 

You sighed, feeling somewhat like a dog with the way Gaster chose his words. You were also a bit irritated at being cut off. 

"I want you to come with me. I don't want you wondering around just yet. I haven't even shown you around."

"Okay." Sans said, following you like you'd requested. 

Papyrus was still on your side, but the opposite one now. He was getting rather heavy and uncomfortable being placed on your other side. Papyrus was still chewing on one of his monster candy. Sans unwrapped one of his and popped it into his mouth as the three of you made your way to Gaster's lab.

"Yes, Gaster?" You asked, peeking into the lab. 

"Ah, there you are." He said, eyeing Sans and Papyrus.

You felt your magic beg to be flared up on what you deemed motherly instinct at this, but tried your best to will it away for the time being. 

"I was...unaware...You were bringing..." He trailed off and you finished for him, afraid he'd say something you'd deem insulting and tackle him on the spot. 

"Sans and Papyrus." 

"Right." He said in a disinterested manner. "Why don't we get someone to watch over them while I run your daily tests?" 

Uh oh. Momma Blaster instincts were on the edge of flaring up. You were trying your best to push it away and hold it back, but it wasn't relenting just yet and probably wouldn't until you were far away from Gaster. Just the way he looked at them almost disgustedly made you wanna get protective of the two. 

"No. Either the boys stay in here while you run the tests or we're not doing them at all." 

"Now you listen here! I created you and you will obey my commands!" That was it, that was the last straw. 

Your straws were all broke now and no more were able to hold back the flaring up of your right eye. 

"Sans, hold Papyrus for me, will you?" 

"Sure thing." You handed Papyrus off to Sans and took a step in front of the siblings, pinning a harsh glare onto Gaster. 

"Don't you dare start with me, Wing Dings. I will kick you so hard you'll fly out of Mt. Ebott."

Had you been a bit more observant and not blinded by rage, you would notice Gaster examining your current posture, the strength of the magic power surging around you, the barrier you had unknowingly formed around the brothers, and how brightly your right eye had shone in comparison to earlier times. Gaster didn't really intend on hurting you or the...other two. 

You played a main role in his research and since the...boy's arrival, you'd changed drastically. It seemed the only way he'd get better quality research was to let you keep the two around and to rile you up. Your powers worked best when you were enraged. He'd prompted you to attack by further making you or the boys feel threatened and easily kept up with your angry attacks. 

He blocked them with his own magic when he needed to, but mainly focused on dodging and examining your movements, strength, weak points, and how far you went before tiring. When he noticed your movements starting to slow, he caught you in a hold, effectively stopping you from hitting him. Not that you could to begin with, though. You were rather strong, however. 

Gaster was just far more experienced than you. Having lived quite a while, before the War and actually taking part in the war. His magic encased your soul, orange turning purple as he lifted you from the ground and held you midair with his magic. 

"Wha- Hey! Put me down you-"

"You're dismissed."

"...What?" 

"You heard me. Stop acting like you didn't, calm yourself, and leave. I have to write down my findings."

Wait...He was just messing with you? Now that made you angry. You banished your angry thoughts of revenge when your soul was released from Gaster's hold and you dropped to the floor painfully. The bastard was just lucky you healed easy or he was really in for it. However, you sighed and picked yourself up off the ground to head over to Sans and Papyrus. 

You were in a losing battle and despite it being quite angering that he was merely toying with you, you tried you best not to lunge at him and fight him what little strength you had left. He was not one to be messed with. Blinded by anger, you'd forgotten he was a survivor of the human and monster war. 

"Come on, you two. Let's get some rest, yeah?" 

However, Sans just stood there, holding Papyrus as if in a daze like earlier. 

"Uh...Sans?" 

"That was awesome! Where'd you learn to fight like that?!" 

"I just did." You were thinking, 'I didn't,' but decided against saying that to Sans. 

"And that Gaster guy...He's so cool! You couldn't even land a hit on him!" You were a bit angered at Sans regarding Gaster as such, but tried your best to look indifferent. 

"Sans, rest awaits." 

"Oh! Okay!" He said, following behind you as you headed to the bedroom.

He and Papyrus sat on your bed as you dug out an extra pillow and blanket from your closet. Papyrus was fast asleep as you turned to the two with pillow and blanket in hand. 

"You two rest easy, alright? If you need anything, I'll be on the couch. I'll give you a tour tomorrow and we can head to the capital to get you and Papyrus some things, alright?" 

"Um...Mom?" 

"Yeah?" 

"Could you...Sleep here? With us?" Sans asked, looking a bit uneasy. It was hard to tell if he was worried about being left alone or if he was unsure about his words. 

"You sure? I figured you'd want to be left alone." 

"I don't want to be alone again. Mom and dad..."

"Hey, it's okay. I'm here for you now, alright? I'll keep you safe and I promise I won't leave you." You said reassuringly as you made your way over to him and Papyrus. 

You placed your pillow down on the far right end of the bed, making yourself comfortable before lying Papyrus in between you and Sans. You pulled the covers over the three of you before hugging Sans and Papyrus close in a motherly, protective manner. Sans clung to your arm tightly while Papyrus snuggled into you for warmth. 

You smiled down at the two, watching Sans drift off and Papyrus continue to sleep before drifting off yourself. You were unaware of the open door and still on light, but you didn't particularly care at the moment. All that mattered was the safety and contentment of your new sons. As Gaster passed by your open door later that night, he spotted you on the bed, light still on and door wide open. 

He was use to seeing your open door or slightly ajar door, but he had at least asked you to turn off the lights when you weren't using them. What? Were you going to disobey him in every way now?! A bit angered, he went to yell at you, but thought against it when he noticed you were fast asleep. He noticed that the boys were wrapped up in your protective hold and felt a new emotion surge through him. 

What was this feeling? It was like anger, but different somehow. With an irritated huff, he flicked off your light and carried on. He hadn't time to feel and figure strange emotions. What was most important was his work and Asgore be damned if things didn't stay that way.

**Notes for the Chapter:**

> Yep. Gaster is feeling jealousy. XD Also, feel free to share your headcannons with me or toss me some ideas. I'm all open towards you sharing your headcannons and ideas. Besides, I'm a bit on the low side on ideas for this story. Help would be greatly appreciated. :)


	4. Visiting the Capital

**Summary for the Chapter:**

> You and the boys head to the capital to do some clothes shopping and also end up getting groceries. However, your trip does not go as planned and the unexpected happens.

**Notes for the Chapter:**

> Okay, so I wanted to expand on why I wrote that some monsters weren't as nice as others. Honestly, I don't think everyone could handle being Underground for so long without at least having something like depression hit them. In the game, most monsters are happy go lucky, trying to cope with being stuck Underground for so long. In my version, things take a darker turn. There are monsters that go 'Corrupt' ;) I'll expand later. I don't want to ruin everything just yet. Also, I thank all you guys for your comments and ideas. I used some of them, but not all. I wanted to take things a bit slow. XD Perhaps I should add the tag 'Slow burn.' However, I'll warn you, sometimes my 'slow burns' don't turn out that slow. Tell me if you feel like I'm going too fast. Also, I want to know, what other things would you guys like to see happen in this story and what kind of ships do you want to sail?

The next morning, you awoke to a hand smacking you in the face. Flinching, you pulled back and opened your eyes to find Papyrus there with his hand still on your cheek. He let out the most adorable giggle as a big smile overtook his features. 

You smiled back and checked on Sans to see him still fast asleep. You moved so that you were sitting up and held Papyrus to your chest as you pulled the still sleeping Sans closer to you. Papyrus tilted his head at you like a dog would. 

"What?" You asked, somewhat confused. 

When you tilted your head a bit, Papyrus laughed. You couldn't help but let a grin take over your features at that. 

"You think that's funny do you?" Still overtaken by giggles, Papyrus did not answer. 

Still smiling, you nuzzled him affectionately. 

"You're so cute." Suddenly, he went quiet again as he stared into your eyes. 

"Mommy." He said, catching you by surprise. 

You recovered quickly, sending him an affectionate look. 

"Yeah." You muttered, pulling him in a tight, but not too tight embrace. "Mommy is here."

Papyrus pulled back and pointed at Sans. 

"Bubbie." He said. 

"Yeah. That's big brother Sans, isn't it?"

"Yes. Big brother Sans okay?" 

"He's just sleeping." 

"Sleeping?" 

"Yeah. He'll be awake soon." 

"When?" 

"I don't know." 

"How come?" 

"Sans will wake up when he's ready." 

"When he's ready?" 

"Yep." 

"Why dark?" 

"Because the light is out." 

"Light out?" 

"Mmhmm. Watch." You said, picking up Papyrus and walking over to the light switch. 

You flipped it on and Papyrus looked amazed. You couldn't help but grin at him. He was so adorable! However, you couldn't help but worry that you may have woken up Sans. He needed all the rest he could get. You went over and checked on him. 

He was still asleep. You then remembered what your plan was for today. You were supposed to take the boys into the city today and get them some clothes and stuff. First, however, breakfast was in order. 

You picked up Sans with your magic, wrapping the blanket from the bed around him and carrying him to the living room with the blue magic still surrounding him. 

Gently, you placed him down on the couch of the living room before heading into the kitchen with Papyrus still on your hip. You thought for a moment over what would be best to make for breakfast. And as much as you currently disliked Gaster, you felt yourself wondering if you should also cook for him too. 

Skeletons topside may not have needed to eat, but all monsters, no matter what type, needed food for their magic to stay stable and at its best. It was like fatigue to a human, only magic is drained, too. 

I mean, it's still drained regardless if you're using it, but food keeps the magic level stable and less likely to collapse on you in battle. Magic can only be used for so long before its like running a mile a minute and fatigue catches up. 

It doesn't help when both your physical energy and magic are both being used and drained at the same time, and you specialized in both physical and magical strength. Huffing after having a tiny internal struggle, you trudged to Gaster's room in anger. 

Why were you letting yourself be swayed by your conscious? He was a threat to the boys. At least, that was the way you saw it. He wanted nothing to do with them and acted as though their very existence was a crime. 

You let out a low growl as you finally reached his door. Letting out a sigh, you raised your hand to knock lightly on the door. 

"Gaster? Gaster, I'm gonna cook. Want anything?" You waited a couple moments before calling again. "Gaster?" You yelled a bit louder this time. 

His light was on, he had to be up, right? Was he ignoring you? Getting a bit agitated, you felt your mind warn you that maybe your next action wouldn't be the greatest idea, but you were opening his door before you could think twice about your decision. 

"He-" You cut off seeing the sight before you. 

Gaster was in his desk seat next to his bed. He'd fallen asleep, arms folded under him and over a big stack of papers. You sighed- your sigh a bit more of a huff than a sigh-and placed your free hand on your hip that wasn't occupied by Papyrus. 

What were you, watching three kids now?! Despite your slight agitation at the situation you sighed and silently approached him, using your magic to drape a blanket over his shoulders. There was a feeling in your chest, one you were beginning to resent. 

Why was it telling you to take care of Gaster, too? It was odd and infuriating. That man wanted nothing more than his research. He'd told you from the start, so why this sudden burst of fee- You dared not let yourself continue that thought. 

Just imagining that sentence really happening made you cringe. No. You would not allow yourself to think that way. You did not have fe- fee- You couldn't even finish the word. Not even in your mind. 

As if a gift from above, Papyrus spoke, breaking your thoughts on Gaster and your position with him. You were his test subject, nothing more, and certainly nothing less. Papyrus pointed a small bony finger at Gaster.

"Daddy?" He questioned. 

You were horrified. Your eyes widened and your mouth fell open slightly. Anger slightly invaded you at his assumption. Gaster was most certainly not their father! He didn't even care for them! He hated them! And to even think you would- No. No! 

You internally began shaking your head and beating yourself up. You were not going to think like that! All Gaster saw you as was a test subject and you were fine with that. You didn't want things to ever go any farther than that. 

"No, that's not daddy, Papyrus." You tried to speak gently to him despite slight anger rushing through your veins along with the horror. 

To even think that Papyrus thought he was his and Sans' dad was preposterous! Well, you could see it from Papyrus' point of view since Gaster was a skeleton, but there was no way you'd ever consider him a part of your adopted family. 

Not with how he treats the kids. Not to mention he was grouchy, cared only about his research, and-

"Then who that?" Papyrus asked.

"That's Gaster."

"G- Gas- Ga-..." Papyrus frowned, clearly a bit angry at his lack of ability to pronounce Gaster's name. Finally he busted out, "'Aster!" 

You couldn't keep the grin from your face or the laugh from escaping your mouth. You just let it go since you couldn't hold it in. 

"Pfft- Ahahaha!" You held your stomach with your free hand as you laughed, but quickly slapped it over your mouth and stiffened when Gaster shifted.

As if sensing your fear, Papyrus grasped tightly onto the shoulder of your shirt and leaned closer to you. He sighed, but made no other moves to get up. 

After a while of waiting, you let out a sigh of relief and quietly turned the lamp on that lay on the other side of the bed on a nightstand. As you left the room, you turned out the light and carefully closed his door as to not awaken him. 

"Never again." You said while looking down at Papyrus, but it was more of a mental note to yourself than anything. 

As you passed by the living room, you found Sans still wrapped up in a blanket and sleeping soundly on the couch. You decided you'd let Papyrus pick breakfast. So, here you were, letting Papyrus look around in the cupboards from his place on your hip. 

"What that?" He asked, pointing at foods as he looked around. Finally, the two of you settled upon pancakes. 

You made one for Papyrus and two for everyone else. If Sans or Papyrus couldn't eat their share, you'd eat it. And if they wanted more, you'd offer them one of yours. That's what your mind had settled upon. 

Momma Blaster sure had a big influence on your feelings since these boys came into your life. You woke up Sans to eat and asked that he watch Papyrus while you sneak in and place the pancakes next to Gaster. You didn't want a repeat of earlier. 

Carefully, you crept in and placed the pancakes at the edge of Gaster's desk so he wouldn't accidentally knock them off in his slumber, but not too close to the edge that they'd fall off and quickly left after placing them down. 

You returned to the kitchen and made sure the boys had their fill before writing a note to Gaster and telling him where you were going and that you were taking some gold.

Despite still being a bit salty towards him, he'd always let you know when he was leaving before and you figured you'd do the same. It was only fair. Besides, you had to be somewhat nice to him. He did provide the roof over your head, after all. 

With the Core still not completely finished, parts of the Hotlands had to be connected other ways until it was finished. You stayed in Gaster Blaster form to protect Sans and Papyrus from falling into the lava below and to protect them from dangerous monsters.

There weren't many, but for some reason, monsters sometimes became 'Corrupt.' They went into a rage and attacked anyone close by. It was still unknown why, but their usual white souls had the tendency to turn black. 

They were corrupted in a sense, but no one knew why. Gaster was still working on that. It wasn't often this happened, but it wasn't unlikely, either. 

You had no problems and made sure Papyrus and Sans were safely seated and latched onto your boney body before you began your journey. Sans and Papyrus observed their surroundings with wonder. 

You often heard 'Woah's, 'Wow's, and 'Oooh's along the way. You couldn't help but smile and glance back at the two. They were adorable. Soon, you reached the capital. There was a barren area beyond the Hotlands. 

Beyond the barren area was the capital, a large city where most of the monsters resided. You weren't one for crowds, but you had nothing to fear. 

Most monsters were nice and those that became Corrupt were often secluded, off to themselves for some odd reason. Most cases you'd heard of involved depressed monsters or ones that just started freaking out at random before going savage.

If they thought the Hotlands were fascinating, they really like the capital. It was a bit crowded, so you had to settle for your human form. You held Papyrus and kept a tight grip on Sans' bony hand. 

You didn't hold on too tight, but tight enough he wouldn't slip out of your grasp and get lost. The first place you headed was to a clothes store. You let Papyrus and Sans pick out their outfits. 

Once you finished clothes shopping, the three of you went to buy more groceries. It wouldn't hurt to stock up on some groceries, you thought. However, you were wrong. You'd set Papyrus down for only a moment as Sans helped you pick out some food. 

During that time, you hadn't noticed that something had gone terribly wrong. When you turned around to check on Papyrus, he was no where to be found.


	5. The Search for Papyrus

**Summary for the Chapter:**

> You and Sans search for Papyrus while Gaster goes over his research notes and tries to learn more about corrupt souls and how to break the barrier.

**Notes for the Chapter:**

> Alright, so I've been thinking for a while now. How would you guys feel about a Underfell and Underswap version of this story? I have a lot of good ideas if you guys are interested. XD Sorry if Undyne seems too nice in this. I didn't exactly want her to be rude and make the reader made with her. That would probably end badly.

You decided to let you magic handle carrying the groceries since you hadn't any other way to pack them. With Papyrus on your hip, you and Sans walked down the isle looking for the food that was low or not in the house. 

" _Water_ you looking at?" You asked Sans, trying to hide a grin at your own pun. 

He turned to you with a box of cereal in hand. He noticed the bottles of water behind you to which his seemingly permanent grin seemed more genuine. You couldn't contain your grin and the two of you ended up laughing together. Papyrus seemed unamused. 

"Just _cruising_ the isle." He said, presenting the car on the cereal box to you. 

After recovering from the awful puns the two of you had thrown at each other, you headed on down the isle. You set Papyrus down at the meat section. As you looked over the meat, trying to decide, a grin settled across your features. 

"There's no ham. What a _misteak._ Ham is great." You said, turning the pack of steak to Sans. 

With a laugh, you used your magic to levitate it and turned to pick Papyrus back up. However, your eyes only saw the floor and your surroundings with no Papyrus. You turned to Sans, horrified. 

"Uh, Sans? Please tell me this is some sort of joke." However, when you saw Sans also had a horrified look, you really began to panic. 

He started to shake, eyes going blank. 

"P-papyrus? Paps?!" He looked to you, lights in his eyes returning, but with tears gathering in the corner of his eyes. 

You may have questioned his ability to form tears had you not been so worried at the moment. You put the meat back with your magic and placed the other stuff that wouldn't wren aside. Hurriedly, you picked up Sans and began to frantically look around the store for him. Sans was holding tightly to your shirt as you began your search for Papyrus. 

-P.O.V. Swap- 

Gaster had been quite shocked to awake to the smell of pancakes. Had he fallen asleep while eating last night? Wouldn't be the first time. Upon sitting up and inspecting them closer, steam was still coming from them. Had you...Cooked for him? Why, this was certainly a first! For a moment, he turned his attention away from the food and looked down at his notes. Where was he again? 

Ah, yes. He'd just finished up his notes on your new found strength and powers. It was time to get onto his research of blackened souls. This had been a problem topside, too. Certain monsters, for some strange reason, had the tendency to go wild and hurt everyone around them. It seemed to be those that were isolated from society and spend copious ammounts of time to themselves. 

They also seemed to contract the human disease known as 'depression.' Souls were known to produce cracks if the monster had been under a lot of stress or suffered from some bad memories. 

'Like the war...' Gaster thought to himself bitterly. 

His own soul held cracks from that war. It had been an awful war, full of blood and violence. It easily explained the lack of monsters in the Underground. Thought Gaster still couldn't deny that the population was coming back up steadily. He only had to worry when there were too many monsters. Which was why he needed to continue soul research and help the King and Queen to find a way to break the barrier.

_______ was very important in his research. She was a human, just what they needed to break the barrier. But how? She still had yet to control her powers. It was unknown yet what could shatter the barrier. Gaster had tried countless things, even the King and Queen themselves tried to break the barrier. Yet there were still no results. It seemed that magic was useless against the barrier. 

Not even _____ had known how to break the barrier. Anything could come in, but nothing could leave. Gaster needed to do something. The whole Underground was counting on him, and the King and Queen to help find a way to break the barrier. Gaster couldn't give up no matter what! Soul power had to be the answer. Gaster thought hard, tapping his finger on the desk as he did so. 

He needed to find some way to break the barrier, and maybe even give those humans one for. No, soul power was too strong. Human souls were a lot stronger than a monster's. An agreement would need to be formed. There was no other way the two species could co-exist otherwise. He grabbed the plate of pancakes and cut the top one before stabbing it and taking a bite as he looked over his notes. 

Hey, these pancakes were pretty good. Could use a little syrup and coffee to go with them, though. So, Gaster grabbed his notes in one hand and carried the pancakes in the other. After making coffee and smothering his pancakes in syrup, he began to eat his pancakes while going over his notes. Wait- This one wasn't one of his notes. The handwriting was different. He began to read over it, a bit confused.

'Hey Gaster, The boys and I are going to the capital to do some shopping. I hope you don't mind I took some gold. We'll be back in a bit -______.' 

Huh. Well, that explains it. At first, it didn't bother Gaster. Why should he care that you took the boys to the capital? You'd be fine on your own. You may not have had precise control over your powers, but you were still fairly strong and he had confidence you'd be able to whipe the floor with any problem that came your way. However, as time passed, he began to grow just a tad bit worried. 

It was well passed the time he'd had breakfast. You should be back by now. What was taking you so long? 

-P.O.V. swap- 

Just when you started to get worried Papyrus may have wondered out of the store, you found him. He was in one of the isles talking to another monster just a bit bigger than he was. They were a fish monster from the looks of it. They had blue skin, two glowing yellow eyes with black slitted pupils. There was a big grin on their face, two sharp teeth peeking out from between her lips. 

"Papyrus!" You shouted in your worried state, running over to embrace him. 

Sans did the same, holding him tight and scolding him. 

"Papyrus, don't ever do that again! You scared us! You shouldn't wonder off on your own." 

"Momma! Bubbie!" Papyrus shouted happily, seeming to ignore the scolding all together. 

It was then you noticed he was holding something. Spaghetti noodles? You stared at them confused. 

"He seemed to be staring at them pretty intensely, so I got them for him." The fish monster spoke, referring to the noodles. 

"Thank you. What's your name?" 

"I'm Undyne! And I'm going to be part of the Royal Guard!" She shouted, very enthused about joining. 

"Well, it's nice to meet you, Undyne. I'm ______, and this is my sons: Sans and Papyrus." Undyne was about to say something before another voice shouted. 

"Undyne!" She flinched slightly and looked a bit worried. 

"I better go. It was nice meeting you!" She shouted, running off in the direction of the voice. 

You had enough time to sigh and turn back to the boys lovingly before you noticed the dark shape behind them. Looking up, you made eye contact with someone you weren't expecting. 

"Gaster? What are you doing here?" 

"You were taking too long, so I came to see what the problem was." 

"Daddy!" Papyrus suddenly shouted, waddling his way over to Gaster. 

The shock was evident on all three of your faces as Papyrus sent a big grin Gaster's way. You were quick to hide your face, a pure red covering your features. Sans' eyesockets went blank and he struggled to hold back laughter. Like you, Gaster's face was flushed, but rather than red, his face was a dark purple. He turned to the side, coughing. 

"Erm. Let's just get the groceries and check out, yes?"


End file.
